Thanks up front, finished the 6j1 board modification as according to your video. Very nice. 🎉🎉🎉 Now, I am on this video that I have longed for couple needles swinging dancing with the music. But I would like to try the bigger size meter. Let’s hope I can complete it. 🎉🎉🎉 I need to digest your video many times as I am a slow learner.😅😅😅
This was extremely useful, thank you so much. I have created a circuit based on yours for my DIY synth. My audio input is +/-5V (10V p-p) and so I used a voltage divider at the input to scale down to +/- 500mV. I added a variable resistor so I could set the scale accurately. I skipped out the second op-amp stage as it didn't seem necessary with such a large input voltage. I kept in the protection diodes and 470 Ohm resistor though. Thank again, it looks great!
Thank you so much for this! Was really struggling to get a meter running from a 5V supply - just put this together on vero board and it works perfectly. Can't thank you enough!
Designing and building a driver for a couple of small VU Meters. 00:00 Intro - Having a close look at the meters 03:45 Looking at design options and requirements 06:20 Breadboard prototype 07:47 Full schematic and design details 12:11 Circuit board assembly 18:44 Testing and changes 21:14 Demo of performance with music sample
This is an excellent little project that will help me a lot in what I am doing. I wonder how this is calibrated. There doesn´t seem to be any variable resistor. Is it just firmly fixed?
Congratulations. Very good work and very neat too. Now... do you find it useful to look at a dB scale? Many amateurs put vu meters just to make the equipment look nice but that doesn't seem to be your case. Wouldn't it be better to change the scale and express it in Watts/8Ω or Watts/4Ω ?
Thanks so much for this! If I was to build a stereo version of this (one VU for each channel), do you know if I would be able to run them off the same rails, including the virtual ground? Would any other modifications need to be made for this? Also I'm assuming C2 is still an electrolytic cap when changed to 1uf. Much appreciate any help!
I'm still learning so please don't take it the wrong way. You want to switch the 10uf to a 1uf ceramic? Did you think about or try using a Mylar/Poly 1uf cap?
You have the right idea, I'd never recommend using a ceramic capacitor for coupling in an actual audio circuit. They are microphonic, not stable with temperature and also changes value based on bias voltage. However while this circuit does take an audio input, it's not really an audio circuit, a bit added distortion from a ceramic capacitor will not have any effect here.
Nice design, I might try to get a pair for an upcoming tube pre-amp project. Have you tried tinning the boards prior to assembly? The tinning solution is expensive "liquid tin" (tin fluoroborate) but it lasts forever and protects the cooper from corrosion (going green) over time and makes soldering much easier. I use it on my home made PCBs. I do just fine with a 125 ml bottle of it. Thanks for the video, cheers,
Thanks, yeah I think these meters would look great in a tube pre-amp and you should be able to power them using a filament supply winding. I do have a few bags of the crystallized tinning powder you mix with warm water and it works well, but these days I mostly just give the board a quick spray with a conformal coating if I'm going to use it long term. I'll probably do a quick follow up video with a final schematic and board design. Cheers - Jake.
yeah, you got the right idea, using a comparator or an opamp with high gain would work, but you might want to add something like charging up a capacitor to add a peak hold kinda effect so it will be more visible once the peak point is reached. Another option would be using a tiny 8 pin microcontroller with an A/D input, then you can just write code to make it behave any way you prefer. Cheers, Jake
@@TheStuffMade Ι've managed to put a peak detector circuit with a comparator on a breadboard and after messing a bit with the resistor values it works okay. I've also breadboarded your circuit and was wondering what changes it would require in order to display the actual VU scale, meaning accepting larger voltages and have a 0 mark at about 1.2Vrms..I suspect since the second stage is a non-inverting configuration and the gain is inherently larger than 1 I would probably need to use a resistor from the (+) terminal to ground to form a voltage divider of the incoming signal.This way the circuit could accurately display VU values as they are with an attenuated input since the incoming signal will be much larger. From what I understand you designed this circuit to accept a signal roughly 10 times less than the actual VU value right? So, for the meter to display +4 VU it would normally require a 1.95Vrms input signal but with your circuit configuration you can reach this value with 200mV signal, if I understand correctly?
wow, this is what I'm looking for but I lack the skills and equipment to build. I wonder if this would work for measuring the output of an electric guitar, though it must be a bit different since the electric guitar emits a sound that is picked up by the insulated wire coil of the bobbins and converted into an electric current by means of an induction process. Current is then transmitted to our amplifier by the cable that connects our guitar to it...most of these bobbins or "pickups" are in the 23.72 Kohm reistance, but am thinking of bulding a guitar with a VU meter display on it that measures the peaks of the signal as one plays..is this possible? Thank you! I didnt want to simply buy the VU meters anbd connect it to the output jacks...
Hello, very nice sharing. I have a few questions, which opamp did you use, what is the value of the large capacitor you installed in the circuit, where did you use this capacitor, what is the minimum supply voltage? Thanks
yow i know how to connect cuz i found a driver with this.. but my problem can i connect this for my power amplifier? 400w ? or this is only for small wattage amplifier?
This design is for line level, if you have a pre-out or use separate pro and power amps, then you can use the signal before the power amp. Otherwise it doesn't matter if you have a 1,000W amp, you can use a resistor divider to get the correct voltage level as it's high input impedance. Perhaps a couple of resistors and a pot to finetune. Just be careful if your amp is class-D or some other bridged output configuration then you need a floating power supply (e.g. separate transformers) for each channel. Cheers, Jake
Yow bro Good day.. i need some help about Vu driver... yesterday i was searching vu driver layout for my diy.. and finaly i found 1 layout.. but it takes many days or months cuz i need to fabricate.. so i try searching VU driver in online selling.. and i found 1, and it says i should connect the input vu driver to amplifier output with 2 resistor series each channel left and right.. so my problem is im so confused about this circuit.. if i will work if ill try to connect this to my pre-out.. even says i should connect to speaker output.. i cant put some link where i found the driver but ill try another ways..
The 2nd part of the opamp functions as both gain and a buffer to drive the meter. One of my requirements is that it must be able to do full scale with just 100mV signal as I'll have a pot for adjustment before the driver circuit.
@@TheStuffMade they came in two parts in my occasion which was not a good idea from the sender because the parts where just laying in a bag an the needle could have been damaged. As you figured out correctly they split at the front in the cover with the screwholes and the rest. You can actually see the led if you look past the needle coil. Its a yellow square
@@davida.2182 That's unfortunate, but good luck they didn't get damaged, I was thinking about taking a knife and see if I could break one open "for science" but in the end I opted against it as I need both of them for a project. Anyway it's good to know they use an LED, that should last a lot longer than any incandescent bulb.
Just a noob question: if I want the audio signal to pass "through" the vu meter and then send it to another audio unit, I have to convert the virtual ground in an actual audio ground?
Wow that is a lot of extra effort to add a couple meters. I’m all about that cool factor but this is not practical whatsoever. It does however hope me to understand why the high end gear is so expensive. Talk about “doing the most”
Nice choice of opamp. And nice circuit. It works only with one channel though, left or right if using stereo signal. To use a single meter on stereo channel I plan adding another rectifier stage to C2 and R11. Do you see any downsides for doing that? Thanks
Thanks, yes you can do that, or even easier as the circuit is high input impedance going into the positive input of the first opamp, and assuming your source is reasonably low output impedance, you can just use a couple of resistors before C1 to mix the two channels together, e.g. 100k+ in value and then adjust R1 if needed (if you lose too much gain). Cheers, Jake
Thanks up front, finished the 6j1 board modification as according to your video. Very nice. 🎉🎉🎉 Now, I am on this video that I have longed for couple needles swinging dancing with the music. But I would like to try the bigger size meter. Let’s hope I can complete it. 🎉🎉🎉 I need to digest your video many times as I am a slow learner.😅😅😅
Very useful video. I thinked that vu meter was moving iron voltmeter. But i was wrong . Thanks for clear all concept.
This was extremely useful, thank you so much. I have created a circuit based on yours for my DIY synth. My audio input is +/-5V (10V p-p) and so I used a voltage divider at the input to scale down to +/- 500mV. I added a variable resistor so I could set the scale accurately. I skipped out the second op-amp stage as it didn't seem necessary with such a large input voltage. I kept in the protection diodes and 470 Ohm resistor though. Thank again, it looks great!
Thanks, I'm happy you found it useful to build your own version.
Cheers,
Jake
Thank you so much for this! Was really struggling to get a meter running from a 5V supply - just put this together on vero board and it works perfectly. Can't thank you enough!
Great to hear it was useful.
Cheers,
Jake
You explained that fantastically, thank you.
This driver was very good ! it's help me got a lot of space for my Isolator ! Thank you !
Thanks! I'm happy you found it useful.
Fantastic video, your explanation is very clear and intuitive. Thank you.
Thanks, I'm happy to hear you found it useful.
Super! I watched it as a thriller!
man I learn so much from your videos
very good job !!
i would love to do that
!
Designing and building a driver for a couple of small VU Meters.
00:00 Intro - Having a close look at the meters
03:45 Looking at design options and requirements
06:20 Breadboard prototype
07:47 Full schematic and design details
12:11 Circuit board assembly
18:44 Testing and changes
21:14 Demo of performance with music sample
Thanks. You solved a 43 year old question for me
nice build and informative video
Thankyou this was really helpful! :)
This is an excellent little project that will help me a lot in what I am doing. I wonder how this is calibrated. There doesn´t seem to be any variable resistor. Is it just firmly fixed?
This is designed to have a dual potentiometer in front where you can adjust the level. Use something like 100k.
Congratulations. Very good work and very neat too.
Now... do you find it useful to look at a dB scale?
Many amateurs put vu meters just to make the equipment look nice but that doesn't seem to be your case.
Wouldn't it be better to change the scale and express it in Watts/8Ω or Watts/4Ω ?
Verynic Professional 👍
Thanks 👍
the best content, exactly what i was looking for!, looking frwd to setup my own desk cnc, would u recommend something?!
Thanks so much for this! If I was to build a stereo version of this (one VU for each channel), do you know if I would be able to run them off the same rails, including the virtual ground? Would any other modifications need to be made for this? Also I'm assuming C2 is still an electrolytic cap when changed to 1uf. Much appreciate any help!
Common ground will work just fine for a stereo version.
Cheers,
Jake
I bought these too. It is an LED inside, you can see it.
I'm still learning so please don't take it the wrong way. You want to switch the 10uf to a 1uf ceramic? Did you think about or try using a Mylar/Poly 1uf cap?
You have the right idea, I'd never recommend using a ceramic capacitor for coupling in an actual audio circuit. They are microphonic, not stable with temperature and also changes value based on bias voltage. However while this circuit does take an audio input, it's not really an audio circuit, a bit added distortion from a ceramic capacitor will not have any effect here.
Great work,
Nice design, I might try to get a pair for an upcoming tube pre-amp project.
Have you tried tinning the boards prior to assembly? The tinning solution is expensive "liquid tin" (tin fluoroborate) but it lasts forever and protects the cooper from corrosion (going green) over time and makes soldering much easier. I use it on my home made PCBs. I do just fine with a 125 ml bottle of it.
Thanks for the video, cheers,
Thanks, yeah I think these meters would look great in a tube pre-amp and you should be able to power them using a filament supply winding. I do have a few bags of the crystallized tinning powder you mix with warm water and it works well, but these days I mostly just give the board a quick spray with a conformal coating if I'm going to use it long term. I'll probably do a quick follow up video with a final schematic and board design.
Cheers - Jake.
Hi new comment on old video hahaha I am so baffled haha need to try make the same circuit but no. Luck
Great video!Thanks for sharing.If I wanted to add a peak led to this circuit how should I go about it? I imagine a comparator would be needed?
yeah, you got the right idea, using a comparator or an opamp with high gain would work, but you might want to add something like charging up a capacitor to add a peak hold kinda effect so it will be more visible once the peak point is reached. Another option would be using a tiny 8 pin microcontroller with an A/D input, then you can just write code to make it behave any way you prefer.
Cheers,
Jake
@@TheStuffMade Ι've managed to put a peak detector circuit with a comparator on a breadboard and after messing a bit with the resistor values it works okay. I've also breadboarded your circuit and was wondering what changes it would require in order to display the actual VU scale, meaning accepting larger voltages and have a 0 mark at about 1.2Vrms..I suspect since the second stage is a non-inverting configuration and the gain is inherently larger than 1 I would probably need to use a resistor from the (+) terminal to ground to form a voltage divider of the incoming signal.This way the circuit could accurately display VU values as they are with an attenuated input since the incoming signal will be much larger. From what I understand you designed this circuit to accept a signal roughly 10 times less than the actual VU value right? So, for the meter to display +4 VU it would normally require a 1.95Vrms input signal but with your circuit configuration you can reach this value with 200mV signal, if I understand correctly?
Great 😃❤❤
wow, this is what I'm looking for but I lack the skills and equipment to build. I wonder if this would work for measuring the output of an electric guitar, though it must be a bit different since the electric guitar emits a sound that is picked up by the insulated wire coil of the bobbins and converted into an electric current by means of an induction process. Current is then transmitted to our amplifier by the cable that connects our guitar to it...most of these bobbins or "pickups" are in the
23.72 Kohm reistance, but am thinking of bulding a guitar with a VU meter display on it that measures the peaks of the signal as one plays..is this possible? Thank you! I didnt want to simply buy the VU meters anbd connect it to the output jacks...
Hello, very nice sharing. I have a few questions, which opamp did you use, what is the value of the large capacitor you installed in the circuit, where did you use this capacitor, what is the minimum supply voltage? Thanks
LM385D as he showed in charts , it is a two channel op amp if i say it correctly! i am not a pro
@@ariaghobadi5409LM358 ore LM385 witch?
where in the design would you place a potentiometer to dim the vu meter needle sensitivity and how many k-s would you use?
Yes, it's meant to have a potentiometer in front of the VU meter input, 100k should work fine.
Cheers,
Jake
@@TheStuffMade Can I do the same with tl072? Can I swap the chip?
yow i know how to connect cuz i found a driver with this.. but my problem can i connect this for my power amplifier? 400w ? or this is only for small wattage amplifier?
This design is for line level, if you have a pre-out or use separate pro and power amps, then you can use the signal before the power amp. Otherwise it doesn't matter if you have a 1,000W amp, you can use a resistor divider to get the correct voltage level as it's high input impedance. Perhaps a couple of resistors and a pot to finetune. Just be careful if your amp is class-D or some other bridged output configuration then you need a floating power supply (e.g. separate transformers) for each channel.
Cheers,
Jake
@@TheStuffMade ahh.. so iy means i just connect it to pre-amp control before amplifier.. kkk thankyou so much brother
Yow bro Good day.. i need some help about Vu driver...
yesterday i was searching vu driver layout for my diy.. and finaly i found 1 layout.. but it takes many days or months cuz i need to fabricate.. so i try searching VU driver in online selling.. and i found 1, and it says i should connect the input vu driver to amplifier output with 2 resistor series each channel left and right..
so my problem is im so confused about this circuit.. if i will work if ill try to connect this to my pre-out.. even says i should connect to speaker output..
i cant put some link where i found the driver but ill try another ways..
DC 12V VU Meter Driver Board Audio Power Amplifier Level Meter Drive Module
Hi dear, vcc is 5v?
please explain me, why we need 2nd OPA? It is second gain stage? or something else?
For me, (on breadboard) scheme working better bypassing 2nd OPA and using 2 red leds instead of 1n4148's
The 2nd part of the opamp functions as both gain and a buffer to drive the meter. One of my requirements is that it must be able to do full scale with just 100mV signal as I'll have a pot for adjustment before the driver circuit.
Did you measure the current throught the lamp?
I have and at 12V it's 50mA... not bad really.
do it works without 12v? only speaker wire
No, it needs something like +5-12V to drive the op-amps and the lights.
@@TheStuffMade and the 6v 12v thing dous it works on 5v usb port of my tv?
@@TheStuffMade and do i need the meter only or the mainbord too?
Can you build one for me
This is only hobby, I don't provide any services or have anything for sale.
Cheers,
Jake
It is an led, i have the Same
Good info, thanks, that's very good uniform light for an LED and nice warm color. I guess you cracked it open, are they easy to open and close again?
@@TheStuffMade they came in two parts in my occasion which was not a good idea from the sender because the parts where just laying in a bag an the needle could have been damaged. As you figured out correctly they split at the front in the cover with the screwholes and the rest. You can actually see the led if you look past the needle coil. Its a yellow square
@@davida.2182 That's unfortunate, but good luck they didn't get damaged, I was thinking about taking a knife and see if I could break one open "for science" but in the end I opted against it as I need both of them for a project. Anyway it's good to know they use an LED, that should last a lot longer than any incandescent bulb.
@@TheStuffMade its not really that spectacular or interesting or useful but just a matter of manufacturing o guess.
Just a noob question: if I want the audio signal to pass "through" the vu meter and then send it to another audio unit, I have to convert the virtual ground in an actual audio ground?
Wow that is a lot of extra effort to add a couple meters. I’m all about that cool factor but this is not practical whatsoever. It does however hope me to understand why the high end gear is so expensive.
Talk about “doing the most”
Nice choice of opamp. And nice circuit. It works only with one channel though, left or right if using stereo signal. To use a single meter on stereo channel I plan adding another rectifier stage to C2 and R11. Do you see any downsides for doing that? Thanks
Thanks, yes you can do that, or even easier as the circuit is high input impedance going into the positive input of the first opamp, and assuming your source is reasonably low output impedance, you can just use a couple of resistors before C1 to mix the two channels together, e.g. 100k+ in value and then adjust R1 if needed (if you lose too much gain).
Cheers,
Jake